The present invention relates to a non-coherent light source for use in therapy such as photodynamic therapy (PDT), particularly using light emitting diodes (LED""s).
Photodynamic therapy involves the administration of a photosensitising drug to an affected area, and its subsequent irradiation with lightxe2x80x94see for example xe2x80x98The Physics of Photodynamic Therapyxe2x80x99 by B C Wilson and M S Patterson, Physics in Medicine and Biology 31 (1986) April No. 4, London GB.
The document GB 2,212,010 discloses a therapeutic light source which uses an array of discrete LED""s as an alternative to lasers or laser diodes. The output of the LED""s is focussed so as to provide the necessary intensity.
The document WO 94/15666 discloses a therapeutic light source specifically for PDT, with an integrated array of LED""s mounted on the distal end of a hand piece. The LED""s are overdriven to give the necessary intensity, and cooled by the flow of water around a closed loop passing along the hand piece. The document U.S. Pat. No. 5,728,090 discloses a somewhat similar device with various different types of head containing integrated LED matrices. These devices require complicated liquid cooling circuits which would add to the cost of the device and add to the bulk of the hand piece, which is disadvantageous for invasive use.
The document U.S. Pat. No. 5,728,090 mentions that the wavelength of the LED""s is between 300 nm and 1300 nm and is selected based upon the particular photosensitive dye used during PDT. However, the wavelengths of LED""s capable of providing the necessary intensity for PDT cannot freely be chosen within that range.
According to one aspect of the present invention, there is provided a light source for therapy and/or diagnosis, comprising a non-planar array of light-emitting diodes conforming with the shape of an external area to be treated or diagnosed.
According to another aspect of the present invention, there is provided a light source for therapy and/or diagnosis, comprising a first array of light-emitting diodes and a second array of light emitting diodes movably connected thereto.
According to another aspect of the present invention, there is provided a light source for therapy and/or diagnosis, comprising an array of light-emitting diodes mounted on the curved inner surface of a housing arranged to cover at least part of the length of a patient.
According to another aspect of the present invention, there is provided a light source for therapy or diagnosis of a patient, comprising an array of light-emitting diodes arranged within a housing, and an aperture allowing a part of the patient""s body to be inserted into the housing, the array being arranged to direct light onto the part of the patient""s body when inserted into the housing.
According to another aspect of the present invention, there is provided a light source for therapy or diagnosis of a patient, comprising an array of light-emitting diodes arranged within a sleeve so as to direct light onto part of an arm and/or hand of a patient when inserted into the sleeve.
According to another aspect of the present invention, there is provided a light source for therapy or diagnosis of a patient, comprising an intraluminal probe carrying on the surface thereof an array of discrete light-emitting diodes.
According to another aspect of the present invention, there is provided a therapeutic light source comprising an air-cooled array of LED""s, the air being vented in the vicinity of the array. In one embodiment, the array is mounted at the distal end of a hand piece suitable for invasive therapy.
According to another aspect of the present invention, there is provided a therapeutic light source comprising an array of LED""s coupled to a light guide for delivering the light to the area to be treated. Preferably, the LED""s are directly coupled without intervening optical devices.
According to another aspect of the present invention, there is provided a therapeutic light source comprising an array of LED""s with emission spectra substantially limited to the range 550 to 660 nm, and preferably to one of the ranges 590 to 640 nm, 560 to 644 nm, 650 to 660 nm, and 550 to 570 nm.
According to another aspect of the present invention, there is provided a therapeutic light source comprising an array of LED""s with peak emission spectra of approximately 430 nm, 470 nm, 505 nm or 525 nm.